Scientists agree: the flatulence emitted by dinosaurs during their reign on earth is THE cause of global warming.

Scientists agree: the flatulence emitted by dinosaurs during their reign on earth is THE cause of global warming.

Researchers have calculated the methane output of sauropods, including the species known as Brontosaurus, and believe it was to as much as 520 million tonnes of gas annually.

Comparing dinosaurs’ flatulent output to the digestive wind of cows, they are convinced the gas could have been a key factor in the warm climate 150 million years ago.

Mark Wellington from Liverpool Tom Moore’s University told the BBC: “Although it’s the dinosaur element that captures the popular imagination with this work, actually it is the microbes living in the dinosaurs’ guts that are making the methane.”

Methane is a more potent greenhouse gas than carbon dioxide, with a stronger ability to trap heat.

Dr Wilkinson and colleague Professor Graeme Ruxton, from the University of St Andrews in Scotland, began to wonder about Mesozoic methane while investigating sauropod ecology.

Research on a range of modern species has allowed experts to predict how much methane is generated by animals of different sizes with the key factor being the total mass of the animal.

Medium-sized sauropods weighed about 20 tonnes and lived in herds of up to a few tens of individuals per square kilometre.

Global methane emissions from the animals would have amounted to around 472 million tonnes per year, the scientists calculated.

The figure is comparable to total natural and man-made methane emissions today. Before the start of the industrial age, about 150 years ago, methane emissions were around 181 million tonnes per year.

odern ruminant animals, including cows, goats, and giraffes, together produce 45 to 90 million tonnes of methane.

Sauropods alone may have been responsible for an atmospheric methane concentration of one to two parts per million, said the scientists.

In the warm, wet Mesozoic, forest fires and leaking natural gasfields could have added another four parts per million.

“Thus, a Mesozoic methane mixing ratio of six to eight ppm seems very plausible,” the scientists wrote.

“The Mesozoic trend to sauropod gigantism led to the evolution of immense microbial vats unequalled in modern land animals. Methane was probably important in Mesozoic greenhouse warming.